Workpieces, including food products, are portioned or otherwise cut into smaller pieces by processors in accordance with customer needs. Also, excess fat, bone, and other foreign or undesired materials are routinely trimmed from food products. It is usually highly desirable to portion and/or trim the workpieces into uniform sizes, for example, for steaks to be served at restaurants or chicken fillets used in frozen dinners or in chicken burgers. Much of the portioning/trimming of workpieces, in particular food products, is now carried out with the use of high-speed portioning machines. These machines use various scanning techniques to ascertain the size and shape of the food product as it is being advanced on a moving conveyor. This information is analyzed with the aid of a computer to determine how to most efficiently portion the food product into smaller pieces of optimum sizes.
Portioning machines of the foregoing type are known in the art. Such portioning machines, or portions thereof, are disclosed in prior patents, for example, U.S. Pat. Nos. 4,962,568 and 5,868,056, which are incorporated by reference herein. Typically, the workpieces are first carried by an infeed conveyor past a scanning station, whereat the workpieces are scanned to ascertain selected physical characteristics, for example, their size and shape, and then to determine their weight, typically by utilizing an assumed density for the workpieces. In addition, it is possible to locate discontinuities (including voids), foreign material, and undesirable material in the workpiece, for example, bones or fat in a meat portion. The data and information measured/gathered by the scanning devices are transmitted to a computer, typically on board the portioning apparatus, which records the location of the workpiece on the conveyor as well as the shape and other characteristics of the workpiece. With this information, the computer determines how to optimally cut or portion the workpiece at the portioning station, and the portioning may be carried out by various types of cutting/portioning devices.
It is desirable to classify randomly sized incoming products (e.g., chicken breast butterflies) into multiple groups for producing different types of end products (e.g., sandwich portions, chicken strips, chicken nuggets, etc.), respectively, such that each of the classified incoming products is optimally suited for producing the particular end product. For example, certain incoming products may be better suited for producing type A end products, while other incoming products may be better suited for producing type B end products. These incoming products should be classified into two groups for producing type A end products and type B end products, respectively.
Current methods of classifying workpieces into multiple groups for producing different types of end products are based on rather simple rules of thumb. An example of a rule of thumb is that some end products are best produced from heavier incoming products, while other end products are best produced from lighter incoming products. In this example, incoming products are weighed and classified to multiple groups based solely on their weight. Naturally, these classification methods are not as accurate as desired. Furthermore, these classification methods do not consider the overall production goals to be met. Specifically, for each portioning process, a user typically sets certain production goals that need to be met. The production goals may entail, for example, specific quantities of various end products to be produced at the end of the portioning process. If classification is carried out based on the weight-based rule of thumb, for example, and if there are approximately equal numbers of heavier incoming products and lighter incoming products, then the classification may produce approximately equal quantities of the end products that are best produced from heavier incoming products (e.g., type A end products) and the end products that are best produced from lighter incoming products (e.g., type B end products). The production goals, however, may actually require that more or less type A end products be produced than type B end products. Then, at the end of the portioning process, the production goals are not met.
A need exists for a method and system for classifying incoming products to produce various types of end products while at the same time meeting overall production goals.